Trip casing spear



April 1, 1930. G. H. cLERKx VAN KEULEN 1,753,074

TRI cAsING SPEAK Filed sepi. 17, 1928 FIGS.

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' tract the string of casings,

Patented Apr. l, 1930 UNITED STATES @,PATEKN'E" QFFICE GODEFRIDUS HENDRIKUS CLERKX VAN KEULEN, OF THE HAGE, NETHERLANDS, AS- SIGNOR TO DE BATAAFSCI-IE PETROLEUM MAATSCHAPPJ, 0F THE HAGUE, NETHER- LANDS TRIP; CASING SPEAR Application led September 17, 1928, Serial No.

This invention relates to trip casing spears as extensively used for extracting strings of pipes or casings sunk in deep wells. SuchV `outwards against the inner wall of the casing and grip the same when said body is hoisted. If it should be impossible by the application of repeated upward pulls and jerks to Vexthe slips should be released by a downward motion of the central body, whereupon the spear should be capable of being pulledout of the well without the slips reengaging and gripping the inner casing walls. To this end the central body is provided with a bottom extension encircled by a coiled spring bearing` with itsv lower end against a collar on said extension and in Contact with its upper end with an annulus releasably locked to the said extension. Vhen the slips engage and grip the casing to be extracted, they serve as fixed abutments which limit the extent of upward motion of the annulus, but on a strong upward pull being exerted on the wedge the annulus is tripped so as to have freedom of upward axial movement over the bottom extension under the iniiuence of the coiled spring. Therefore, if the casing cannot be extracted and the wedge is lowered through a short distance, whereby the slips disengage the inner casing wall, the annulus pushesthe slips upward relative to the wedge so as to `keep them out of contact with the said wall when the spear is pulled out of the well.

ln these known devices, the slips, the wedge, the spring loaded annulus andthe trip require a very exact relative setting in order that the slips may cause the annulus to be tripped in the moment wherein they have gripped the casing with just s ufhcient force not to be raised'under the influence of the spring. This relative setting of the operative parts can, however, be effective only when the casing to be extracted has throughout the exact inner diameter for which the spear has been designed, but unfortunately 306,565, and. in the Netherlands .Tune 19, 1928.

certain tolerances to which manufacturers are working and also to the fact that casings of the same size are made in various weights, which entails various diameters.

Now, the object of the present invention is a trip casing spear, the operation of which is not interfered with by the normal variations in the inner diameter of the pipes, so that the annuliis is always tripped with certainty. Y

In accordance with the invention, the casing spear is provided with a central bar adapted to be pushed downward either under the action of the jar, or through a yoke ooacting with an auxiliary pipe sunk into the casing, or through a weight, or in another manner, whereby it forces the annulus down through the medium of a cross bar, yor a bridge-piece, so that the annulus is tripped. In this manner, the tripping is rendered independent of the operation of the slips. It will be understood ythat the novel tripping device may be combined with the conventional construction outlined above.

The annexed drawing illustrates, by way of example, but not of limitation, three different embodiments of the invention. On this drawing:

`Fig. l is a longitudinal sectional elevation of a-complete trip casing spear iii a position wherein the slips have firmly gripped the casing but wherein the trip has not yet been pulled out of its hole. y

Fig. 2 is a longitudinal sectional elevation of part of another device, in which the tripping Vis `effected, through an auxiliary pipe sunk into the casing.

Fig. S is a longitudinal sectional elevation of part of still another embodiment, in which thetripping is brought about by a weight adapted to be lowered within an auxiliary pipe.

F'g. 4 is a longitudinal sectional elevation of the tripping device, on an enlarged scale.

Fig. 5 is a cross sectional plan view along the line V-V in Fig. l.

Sunk into the casing 8 to be extracted is a central wedge-shaped body l0, the top part 11 of which is coupled with a jar9 suspended from a string of rods not shown. Said wedge todo the work owing,

has a cylindrical bottom extension 12 and cooperates with the usual slips 13. Associated with the bottom extension 12 through a trip 15 is the annulus 14 which is loaded by a coiled releasing spring 17 bearing affainst a nut 18 screwedl upon the lower end or said extension 12; he trip 15 is loaded by a coiled locking spring 16 and located within a hole 26 of the annulus, said hole being 'closet-l by means of a screw 27.v

The extension 12 is provided with a recess 19 for accommodating a cross bar or bridge piece 20, the ends or which extend into recesses 21 of the annulus 14, see Fig. 4.

Located within a central bore hole of jar 9 is a push bar 22. Another push bar 23, located in alignment therewith in a central bore hole of the wedge 10, 11, is supported with its lower end by the bridge piece so that, when the movable part ot' the ar 9 is lowered,

the bar 23 through the bridge piece 2O forces the annulus 14 down.` It should be assumed that the wedge 10 has been firmly clamped be- `tweenthe slips 13 so that it canl only be `forced down by a heavy blow. The recess 19 has an axial length permitting the Vannulus 14 to move down through the required distance (Fig. 4)whereby the undercut head 24 of trip 15 disengages the inclined top wall of the recess in the bottom extension 12 so that spring 16 can pushthe trip outwards. Besides, said head 24 moves uphill over a sloping surface 25, whereby the trip is positively forced outwards, even it spring 16 should fail for instance, to the presence of dirt.

It it is desired to also use the conventional device described in the preamble, the recess in the extension 12 for receiving the head 24 or' the trip 15 may be made helicoidal, so that the axial position of the locked annulus 14 relative to theextension 12 can be varied.

According to Fig. 2, a yoke 29 has freedom of axial movement in a recess 30 of an inter mediate part 28 between the jar 9 and the top portion 11`of the wedge 10. An auxiliary pipe 3l sunk into the casing 8 is adapted to exert pressure upon the yoke 29, which again transmits said pressure to bar 23.

rI`he wedge 10 may so forcibly be clamped between the slips 13, that the jar'9 can be uuscrewed and a pipe 32 (Fig. 3.) provided at its lower end with a threaded socket 33 may be screwed to the top portion 11 of the wedge 1l). The weight oi' this pipe 32 maybe sut ticieu't to disengage the wedge A10, otherwise heavy blow on said pipe will have the desired effect, it being understood that a weight (not shown) lowered into said pipe 32 and exerting the required pressure upon the vpush bar 23 should previously trip the annulus 14.

Claims:

l. In "a trip casing spear, the combination of a central wedge-shaped' body,- gripping A slips adapted yto be' Vforced radially outwards of a centralwedge-shaped body,

down relative to said` body,

by upward movement of said body, an annulus adapted to exert upward pressure upon the slips and keep the same in inoperative position, a spring adapted to exert upward pressure upon the said annulus, means for locking saidy annulus against axial movement relative to said body, a central push bar adapted to exert downward pressure upon said annulus so as to displace it against the action of said spring and cause it to be tripped, and meansoperable from above whereby downward pressure can be exerted upon said bar.

2. In a trip casing spear, the combination gripping slips adapted to be forced radially outwards by upward movement ofv said body, an annulusadapted to exert upward pressure upon ythe slips and keep the same in inoperative position, a spring adapted to exert upward pressure upon the said annulus, a trip located within a hole of the annulus, a recess in'said body for receiving a projection of said trip, a sloping surface forming a wall of said recess and adapted to positively push saidA trip out ot said recess when the annulus is moved a centraly push bar adapted to vexert downward pressure upon said annulus so asto displace it against the action of said spring andcause it to be tripped, and `means operable from above whereby downward pressure can be exerted upon said push bar.

3. I n a trip casingV spear, comprising a central wedge-shaped body,- gripping slips cooperable therewith, an annulus adapted to exert upward pressure upon the slips to keep the same in inoperative position, means adapted to exert upward pressure upon said annulus; means for llocking said annulus against axial movement relative to said body, and a separate, positive means for disengaging Isaid locking means, whereby said annulus may exert upward pressure upon said slips.

4. Ina trip casing spear, comprising a central wedge-shaped body, gripping slips cooperable therewith, an annulus adapted to exert upward pressure upon the slips to keep the same in inoperative position, means adapted to exert upward pressure upon said annulus; Vmeans for locking said annulus againstvaxial movement relative to said body, and a separate, substantially centrally-located, positive means for disengaging said locking means, whereby said annulus may exert upward .pressure upon said slips.

5. In a trip casing spear, comprising a central wedgeshaped body, g ip-ping slips cooperable therewith, an annulus adapted .to exert upward pressure upon the slips to lkeep the same in inoperative position, means adapted to exert u ward pressure upon said annulus; alatch $61* locking said annulus against a'xial movement relative to saidbody,

iso

and an axially-movable rod for disengaging said locking means, whereby said annulus may exert upward pressure upon said slips.V

6. In a trip casing spear, comprising a central wedge-shaped body, gripping slips cooperable therewith, an annulus adapted to exert upward pressure upon the slips to keep the same in inoperative position, means adapted to exert upward pressure upon said annulus; said annulus having a recess extending inwardly from the outer periphery thereof, a latch in said recess for locking said annulus against axial movement, relative to said body, a member to which said latch may secure said annulus, resilient means adapted tourge said latch outwardly ot said recess and away from the member to which it is late-hed, said latch normally being in its latched position, and an axially-movable, substantially centrally located rod for positively releasing said latch, whereby said annulus may exert upward pressure upon said slips.

7. In a trip casing spear, a central wedgeshaped body, having a downwardly-extending extension thereon, gripping slips cooperable with said body, an annulusarranged about said extension and adapted to exertupward pressure upon the slips, to keep the same in inoperative position,- said annulus having a recess extending inwardly from the outer periphery thereof, a latch in said recess having a head on its inner end, resilient means adapted to urge said latch outwardly of said recess and away from the extension, said extension having a recess cooperating with said iirst-mentioned recess, and in which said head normally engages, said last-mentioned recess extending outwardly and downwardly at its lower extremity, and centrally located means positively actuating said annulus to force it downwardly whereby the latch may be released, at which time it may exert upward pressure upon the slips.

In testimony whereof VI have signed my name to this speciiication.

GODEFRIDUS HENDRlKUS CLERKX van KEULEN. 

